Abstract We investigate the effect of local parity-time ( PT ) symmetric operation on quantum teleportation in non-Markovian environments, focusing on resonant and off-resonant regimes. An exactly solvable two-qubit model with independent structured reservoirs is built to derive the average teleportation fidelity. We show that the PT symmetric operation lead to oscillatory fidelity decay with local revivals instead of monotonic decay, and optimally PT symmetric operation can stably keep the average fidelity above the classical 2/3 limit even in off-resonant non-Markovian regimes, effectively protecting the quantum advantage of teleportation.
Abstract We investigate the effect of local parity-time ( PT ) symmetric operation on quantum teleportation in non-Markovian environments, focusing on resonant and off-resonant regimes. An exactly solvable two-qubit model with independent structured reservoirs is built to derive the average teleportation fidelity. We show that the PT symmetric operation lead to oscillatory fidelity decay with local revivals instead of monotonic decay, and optimally PT symmetric operation can stably keep the average fidelity above the classical 2/3 limit even in off-resonant non-Markovian regimes, effectively protecting the quantum advantage of teleportation.
Abstract In this work, we investigate the effect of a parity-time ( PT ) symmetric operation on the dynamic behavior of quantum dense coding for a two-qubit system in non-Markovian environments. First, we derive the explicit expressions of quantum dense coding for an exactly solving model consisting of two qubits interacting with an independent structured reservoir. Then, we give two cases, i.e. resonant and off-resonant regimes, to demonstrate the performance of the PT symmetric operation on quantum dense coding dynamics. By investigation, we find that the capacity of quantum dense coding can be obviously enhanced with the assistance of the PT symmetric operation in different regimes. In addition, we show that the optimal local PT symmetric operation can completely protect quantum dense coding. The obtained results imply that the PT symmetric operation method may have potential applications in quantum decoherence control.
Abstract Quantum teleportation, a cornerstone of quantum information processing, faces critical challenges from environmental noise such as amplitude damping (AD), which degrades entanglement and reduces teleportation fidelity below the classical limit of 2/3. This study investigates the role of parity-time ( PT ) symmetric operations, a type of non-Hermitian operation, in enhancing teleportation fidelity under AD noise. We first derive the explicit dynamics of entangled states subjected to AD noise using Kraus operators, showing that the average fidelity decays monotonically with increasing decoherence strength. By introducing local PT symmetric operations, we show the average fidelity exhibits periodic linear oscillations, with minimum values increasing with non-Hermiticity and remaining above 2/3, while maximum fidelity consistently reaches the optimal value of 1. These results confirm that non-Hermitian operations effectively protect quantum teleportation fidelity, maintaining stability and optimal performance despite parameter variations. Experimental feasibility is discussed using nuclear magnetic resonance systems with duality quantum computing techniques.
Abstract In this work, we investigate effect of parity-time ( PT ) symmetric operation on the dynamic behavior of entanglement for two qubits system in Markovian and non-Markovian regimes with the resonant and off-resonant cases. First we derive the explicit expressions of concurrence quantifying entanglement for an exactly solving model consisting of two qubits interacting with independent structured reservoir. Then, we give two schemes, i.e. pre- and post- PT symmetric operations, to show the performance of PT symmetric operation on entanglement dynamics of two qubits. By investigation, we find that the lower the absolute value of the PT operation strength, the better the enhancement of entanglement. In addition, we show that the entanglement can be obviously enhanced by means of the pre- PT symmetric operation in different regimes.
Abstract The dynamic behavior of the relative entropy of coherence for a two-level system is systematically investigated within non-Markovian environment. We derive the exact expressions of relative entropy quantifying coherence for an exactly solving model consisting of single qubit interacting with independent structured reservoir. By employing local non-Hermitian operation, i.e. parity-time ( PT ) symmetric operation, we show that the vanished quantum coherence can be effectively restored under the non-Markovian regimes. Furthermore, the freezing phenomenon of the coherence can be detected by using the optimal PT symmetric operation strength within the non-Markovian environments.
We investigate the standard quantum teleportation protocol for a single-qubit state, focusing on the scenario where the qubit undergoes a class of non-unitary evolution governed by parity-time ( \mathcal{PT} 𝒫 𝒯 )-symmetric non-Hermitian Hamiltonians. Additionally, we examine the case where the entangled pair shared by Alice and Bob is exposed to a noise channel. In the \mathcal{PT} 𝒫 𝒯 -symmetric regime, the teleportation fidelity exhibits time-dependent oscillations. Compared to the conventional case without non-Hermitian operations, periodic enhancements in fidelity are observed, and we analytically derive their dependence on the parameters of both the non-Hermitian Hamiltonian and noise channel. When the \mathcal{PT} 𝒫 𝒯 symmetry is broken, the fidelity ceases to oscillate and instead decays to a steady value. Notably, even in this regime, non-Hermitian operations can yield fidelity improvements over conventional schemes. We further investigate the teleportation of quantum Fisher information (QFI) and find that its evolutionary behavior differs from that of fidelity. Analytical results reveal that QFIs corresponding to different estimated parameters exhibit distinct outcomes at Bob’s receiving end during teleportation. Furthermore, we derive a trade-off inequality between fidelity and QFI, offering a theoretical tool to coordinately optimize these two quantities in the teleportation process.
Abstract Quantum teleportation fidelity is severely degraded by environmental noise, especially correlated amplitude damping (CAD) decoherence with non-negligible memory effects, which is more practical in high-rate transmission. This paper investigates enhancing teleportation fidelity under CAD noise using parity-time ( PT ) symmetric operation, we first analyze teleportation dynamics under CAD, showing its average fidelity outperforms uncorrelated amplitude damping. Moreover, we show that the PT symmetric operation could drastically enhance the fidelity in CAD noise. Results demonstrate PT symmetric operation significantly boost average fidelity, which remains above the classical limit of 2/3. Optimized via adjusting non-Hermitian parameters, the fidelity can even reach 1. Our results extend the ability of PT symmetric operation as a technique in various quantum information processes which are affected by correlated noise.